Control mechanism for circuit breakers



Sept- 19, 195o M. E. HQRN mL 2,523,116

CONTROL MECHANISM FOR CIRCUIT BREAKERS I" L", v N ATTORNEY W 0 Neff E H0772 and Sept 19, 1950 M. E. HQRN fr AL 2,523,116

CONTROL MECHANISM FOR CIRCUIT BREAKERS BY gl/ @W ATTORNEY Sept. 19, 1950 M. E. HORN x-:rAL 2,523,116

CONTROL MECHANISM FOR CIRCUIT BREAKERS Filed Jan. 14, 1944 3 Sheets-Sheet 3 Q I 1 l l l Na j l 213 l M5 [malaria/2f 2151 I l 211'/ 217 man ely n l l f* I I 22j l l 209 122 a? wlTNEssEs: INVENTORS L@ Mer! E Hom and Tur-e Lirzfdsf/a/vzA @www @l Patented Sept. 19, 1950 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR CIRCUIT BREAKERS Application January 14, 1944, Serial No. 518,206

(Cl. F75-294) 13 Claims.

The invention relates to a motor operated circuit breaker and control system therefor.

An object of the invention is the provision of an improved motor operated circuit breaker, of they trip-free type that is relatively simple, very compact, and relatively inexpensive to manufacture.

Another object of the invention is the provision of a trip--free circuit breaker with an improved motor operating means for closing the circuit breaker embodying means for automatically resetting the circuit-breaker mechanism following tripping of the circuit breaker.

Another object of the invention is the provision of a trip-free circuit breaker with an improved motor operating means for closing the breaker, said motor operating means having a resetting mechanism operable to automatically reset the circuit-breaker mechanism and the motor operated closing means following tripping of the circuit breaker.

Another object of the invention is the provision of a trip-free circuit breaker with an improved motor operating mechanism embodying a relatively compact spring means automatically operative to reset the breaker mechanism following tripping of the breaker.

Another object of the invention is the provision of an improved motor operated circuit breaker as described in the preceding paragraph, wherein the resetting spring is connected in a novel manner between the breaker operating lever and the motor operated closing lever so that the resetting moment of the spring applied to the breaker operating lever increases as it approaches the end of the resetting stroke to provide sufcient force to reset the circuit-breaker latching means.

Another object of the invention is the provi- :sion of a trip-free circuit breaker with a motor operating means and a novel and improved antipump control system therefor.

Another object of the invention is the provision of a trip-free circuit breaker with a motor oper- `ating means and an improved anti-pump control system which does not require a motor contactorr and relay.

Ano-ther object of the invention is to provide a circuit breaker with an improved power operated closing mechanism wherein a spring is operable upon release of the breaker mechanism to effect a resetting operation of the breaker mechanism, said spring applying its force through a greater moment at the end of the resetting stroke than at the start of the stroke.

Another object of the invention is to provide a circuit breaker having means for automatically resetting the breaker mechanism following a tripping operation with improved motor operated closing mechanism wherein energization of the closing motor is controlled by a drum switch operated by the motor.

Another object of the invention is to provide a circuit breaker having a supporting frame for the breaker mechanism with a motor operated closing means, said motor and closing means being rigidly mounted on the supporting frame in front of the breaker mechanism to maintain the correct relation between said closing means and the breaker mechanism and to provide a very compact structure of relatively small vertical and horizontal dimensions.

The novel features that are considered characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to structure and operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of one embodiment thereof when read in conjunction with the accomanpying drawings, in which:

Figure 1 is a side elevational view, partly in section, of a circuit breaker embodying the invention,

Fig. 2 is an elevational View similar to Fig. 1 but showing the breaker in the tripped open and reset position, and

Fig. 3 is a diagrammatic view of the electrical circuits and apparatus embodying the invention.

Referring to Figure 1 of the drawings, the reference numeral I l designates a base of strong insulating material which supports the various parts of `the circuit breaker. A pair of terminals I3 and i5 are suitably secured to the base and each terminal has one or more connecting studs I9 which extend through the back of the base Il and serve to electrically connect the breaker to the circuit which it controls.

The upper terminal I3 has a contact block 2| of rigid conducting material secured thereto; and a rigid contact block 23 secured to the base is electrically connected to the lower terminal I5 through the energizing winding of the trip device of the breaker, which will be hereinafter described.

The contact means and mechanism of the circuit breaker illustrated are similar to the circuit breaker fully disclosed in Patent No. 2,214,471 ssued September l0, 1940 to Leon R. Ludwig and Meri E. Horn, and assigned to the assignee of the present invention. Hence only a brief description of these parts will be given in this applicatlon.

The main stationary contacts and 21 are rigidly secured to the contact blocks 2| and 23, respectively; and the auxiliary stationary contacts 29 and 3| are secured to a triangularlyshaped contact platform 33 of conducting material which is mounted on the upper portion of the block 2| for limited tilting and rocking movement by means of pins 35 projecting from the opposite sides of the platform which engage in slots 31 provided in a pair of side walls 39 secured.

to the block 2|. The platform 33V isbiased outwardly from the base I by a plurality of'springs 4| and 43, and outward movement of the platform is limited by the engagement of the pins 35 with the outer ends of the slots-31v and by stop projections carried by the platform adjacent its upper end. The platform 33 and, consequently, the auxiliary contacts 29 and 3| are electrically connected to the terminal I3 by-means of a ilexible shunt conductor 41.

The movable contact means of the circuit breaker comprises a channel-shaped contact arm 49-of conducting material which is rigidly secured to a pivoted switch member 5| by means of a plurality of screws 53. The contact arm 49 carries a main contact bridging member for bridging the main contacts 25 and 21, and an auxiliary contact member 51 for engaging the stationary auxiliary contacts 29 and 3|, the auxiliary contact member 51 being secured to the upper end of the channel-shaped contact arm 49 by a` plurality of screws 59.

The main contact bridging member 55 is formed of rigid conducting material, and is loosely mounted on the contact arm 49 for limited movement relative to the contact arm toward and away from the main contacts 25 and 2-1 by means of a pairof studs 6| secured to the contact carrying arm 99, only one stud being shown. A pair of coil springs (not shown) encircle the studs 6|, andare disposed between the contact carrying arm 49'and the bridging member 55 for biasing the bridging member toward the stationary maincontacts 215 and 2-1 with a predetermined force. The ends of the bridging member 55 are beveled to lie parallel with the beveled edges of the contact blocks 21| and 23, and have apair of` contacts 51 Ysecured'thereto lfor engaging the main stationary contacts 25 and 21.

The auxiliary contact member 51 is formed of rigid-4 conducting material, andl has an intermediate contact 69 vand an arcing-contact1l secured thereto for engaging the intermediatefand farcing contacts 29 and 3|` of the stationary contact means.'

A' ilexible shuntconductor- 13 electrically connects the auxiliary contactarm 49 to the mainstationary contact block 23. The flexible conductor 13 has its upper end` secured to the contact arm 49 by the bolts 53. The lower end of the lexible shunt conductor 13.is secured tothe lower contact block 23 by means of a bolt-11.

The switch member 5| has a yoke-shaped lower end which is pivotally mounted/between the side walls of a main frame 19 byv means of` the pivot pinl.. The switchmember 5| ismovable aboutl i opening of the movable contact means.

4 on the pin 81 for movement about the same axis as the actuating lever 85. The actuating lever 85 is normally releasably connected to the oper'- ating member 9| for movement thereby by means of a pair of latches 93 and 95, which are pivotally mounted on the lever 85 at 91 and 99, respectively. The latches 93 and 95 are biased to latching position by springs 96 and 98', respectively. The latch 93 engages a roller |0| carried by the operating member 9|, and this latch is, in turn, held in latchingposition by the auxiliary latch 95. The operating member 9| is adapted to be releasably held in closed circuit position by means of a main holding latch |03 pivoted at I9, which releasably engages the .roller |.0.|. The auxiliary latch is provided with a curved tailpiece |05 disposed to one-side of the latch 93 by means of which it is released to cause release of the latch 93 and consequent tripping of the circuit breaker by the release of the actuating lever 85 from its connection with theoperating member 9|. When released the actuating member 85 moves in a counterclockwise direction about the pivot axis 81 independently of the operating member 9|, causing During this movement, a cam surface |01 of the lever 85 engages the rounded nose of the main holding latch |03, moving the holding latch to released position to eiect release of the operating member 9|. The switch member 5| and the actuating lever 85 are biased to open position by means of a pair of accelerating springs |09 (only one being shown), which are connected at their upper ends to the switch member 5|. and at their lower ends to the sides of the main frame 19.

To close the circuit breaker after it has been tripped open, the operating member 9| is first moved in a counterclockwise direction about the pivot axis 81 to the open position to effect resetting of the latches and reestablishment of the releasable rigid connection between the actuating lever 85 and the operating member 9|. After the rigid connection is thus established, the operating member 9| is moved in a clockwise direction to closed position by means of a motor operated closing mechanism indicated generally at to eiect closing of the contact means of the breaker. The clockwise 0r closing movement of the operating member 9| is limited by a portion 92 thereof striking a xed stop 94 on the frame 19. When the parts have been moved to closed position, the main holding latch |03 reengages the roller |0| to hold the operating member in closed position. The stop 94 is located to permit a. slight overtravel of the member 9| to insure proper engagement of the latch 03 with the roller |0|. It will be noted that the construction of the operating mechanism is such that the movable contact means is trip-free of the operating member 9|; that is, when the breaker is tripped, the Contact means move to open position irrespective of the position of the operating member 9|.

The mounting arrangement of the contact means is such that during opening of the breaker the main bridging member 55 is rst separated from the stationary contacts 25 and 21, while the auxiliary contacts remain in engagement by reason of the outward movement of the contact platform 33 under the inuence of the biasing, springs 4| and 43. After the bridging member 55 has separated a predetermined distance from the main stationary contacts, the intermediate contacts 29- and 89 begin'to separate. This takes place as soon as the pins 35 engage the ends of the slots 31. During this time, the arcing contechs 3| and 1i remain in engagement due to the rocking movement of the contact platform 33. After the intermediate contacts have separated a predetermined distance, the arcing contacts 3| and 1| begin to separate. During closing, the contacts engage in the reverse order, as will readily be understood. It will thus be seen that the arc formed during separation of the contacts is drawn only between the arcing contacts 3| and 1|.

The circuit breaker is adapted to be tripped open either manually, or automatically, in response to predetermined overload conditions in the circuit, by means of a trip device indicated generally at II5.

The trip device comprises a trip lever I I1 which is pivotally mounted intermediate its ends on the frame 19 by means of a pivot pin II9, and an electromagnet, indicated generally at |2|, which is operable in response to the predetermined overload conditions to move the trip lever I I1 to tripping position to cause automatic opening of the circuit breaker.

One arm |23 of the trip lever I I1 is offset and extends inwardly toward the base of the circuit breaker, and has its inner end disposed immediately above the electromagnet |2I to be engaged and moved by a plunger of the electromagnet to effect automatic tripping of the breaker. The arm |23 of the trip lever is provided with a projection |25 which is adapted to engage the curved tailpiece |05 of the auxiliary latch 95 to move this latch to released position upon movement of the trip lever to tripping position. The other arm of the trip lever I |1 forms a handle |21 whereby the trip lever may be manually moved to tripping position to effect manual opening of the circuit breaker. A spring |29 connects the arm |23 of the trip lever ||1 to an extension of the main holding latch |03 so that the spring thus serves to bias the main holding latch to latching position and the trip lever to its normal inoperative position, as shown in Fig. 1.

The electromagnet |2| comprises a stationary core member |3I, a movable armature |33 having a trip rod thereon, and an energizing winding |31 having one end connected to the contact block 23 and the other end connected to the terminal I5.

Upon the occurrence of an overload of a predetermined value, the electromagnet I2| is energized a suflicient amount to attract the armature |33 and thrust the trip rod |35 upwardly to trip the breaker. When the armature |33 is attracted the upper end of the trip rod engages the arm |23 of the trip lever ||1 and actuates the latter to effect opening of the contacts in the previously described manner.

The circuit breaker is closed by means of the power operated mechanism III. The closing mechanism comprises a motor |39 rigidly supported on a casting |4I having a base |43 of insulating material secured thereto. The insulating base is, in turn, rigidly secured by means of bolts to the main frame 19 of the breaker. The casting |4| forms a housing for a reduction gearing (not shown) through which the motor |39 drives a crank arm |41. The crank arm is rigidly mounted on a shaft |49 for rotation therewith, the shaft being mounted for rotation in bearings (not shown) suitably supported in the casting |4I. Pivotally mounted on a pin |5| supported in the casting |4| and in a yoke portion |53 integral with the casting is a closing lever |55 which is connected by means of a link 51 to the operating' member 9|. The link |51 is connected to the lever |55 by means of an adjusting rod |59 which threadedly engages the lower end of the link and is locked in position by a lock nut |6I. The lower end of the rod |59 is pivotally connected to the lever |55 by a pivot pin |63 supported in the bifurcated end of the lever. The other end of the link |51 is pivotally connected by means of a pivot pin |65 to a bracket |61 rigidly secured to an insulating block |69. The block |69 is secured to the operating member 9|. A spring |1| compressed between the closing lever |55 and a projection |13 extending from the upper end of the link |51 is disposed to bias the bracket |61 and the operating member 9| in a counterclockwise resetting direction about the pin 81. The spring |1I is retained in telescopic tubes |15 and |11 which are pivotally connected by means of pins |19 and IBI respectively to the closing lever |55 and the projection |13 of the link |51. The spring |1| is compressed between a stop |83 (Fig. l) in the tube |15 and a similar stop |85 in the tube |11. The force of the spring |1| biases the closing lever |55 and the link |51 in opposite directions about the pivot pin |63, `but since the lever |55 is mounted on the xed pivot I5I and the link |51 is connected to the operating member 9|, the force of the spring acting through the link |51 biases the operating member 9| in a counterclockwise direction about the pivot 81. The member 9| is normally held against movement in this direction by the latch |03 cooperating with the roller |0| on the member 9|.

When an overload of predetermined magnitude occurs, the trip magnet |2| operates the latch to release the actuating lever 85 from the operating member 9| and permit the springs |09 to open the contacts. As was previously described, during the opening movement of the actuating lever 85, the surface |01 engages and operates the latch |03, thus releasing the operating member 9|. The member 9| is immediately actuated counterclockwise to resetting or relatching position (Fig. 2) by the spring |1| in order to reset the latches 93 and 95 and to reconnect the operating member 9| to the actuating member 85. The relatching occurs during the latter part of the counterclockwise travel of the operating member 9|. The spring |1| continuously expands during the relatching movement of the mechanism, but the lever arm by which the force of the spring is applied to operate the operating member 9| in relatching or upward direction about the pivot 81 increases as the member 9| moves upwardly, thus increasing the spring force available for the relatching operation.

Referring to Fig. 1 which shows the breaker in the closed position, the spring |1I produces a moment about the pin |63 which tries to move the link |51 ccunterclockwise about pin |63 and to separate the pins |5| and |65. Since the link |51 is pivotally connected at |65 to the operating member 9|, the pin |65 must follow a circular path about the fixed pivot 81. It will be noted that the pin |05 is over center to the right of a line indicated at A drawn through the centers 81 and |5I. By extending the line of the force indicated at B, between pins |5| and |65, it may be seen that the position of the pin |65 provides a moment arm indicated at C with which the force produced by thespring |1| along the line B tends to move the operating member 9| counterclockwise about its pivot 81; by the latch: |03 which restrains the member 9|A in the position shown in Fig. l. Upon release of the member 9| in the previously described manner, the member 9| rotates counterclockwise about its pivot 81 thus increasing the distance between the pins |95 and |5|, permitting theV spring |1| to expand. The spring 1| expands very slowly during the early part of the resetting movement since the pin |65 at the start ofk the movement is close tothe line A. As the resetting movement progresses the spring |1| extends itself moving the operating lever 9| to the position shown in Fig. 2, and since the lever 9| is connected by means of the link |51V to the closing lever |55, this lever is moved therewith to itsA Fig. 2 position. It may be noted that while the link |51 is connected to the outer ends of thelevers 9| and |55, the lower end of the spring |1| is connected to the lever |55V at a point approximately midway between the ends of thelever. expands and the upper end of the spring moves upwardly, the lower endI of the spring follows but at a slower rate of speed. It may also be noted that as the resettingr movement progresses thev lever arm C progressively increases as indicated in Fig` 2, so that the reduced strength of the expanding spring |11. is applied through a greatly increased lever arm to produce a greatly increased torque on the lever 9| about the pivot 81 at the end of the resetting movement for resettingV the latch mechanism.

After the latches 93 and 95 are reset and the actuating lever 85 is reconnected to the operating member 9|, the closing lever |55 is operated by the motor mechanism from its Fig. 2 position to the position in which it appears in Fig. l. During this movement the lever |55 acting through the link |51 moves the operating lever 9| and the actuating lever 85', which is now connected to the operating lever, clockwise about the pivot 81 to close the contacts. As previously set forth, the motor |39 rotates the crank arm |41 through the reduction gearing (not shown) encased in the housing lill. hecrank arm |41 (Figs. l and 2) as a point near its free end carries a pin |81 upon which is rotatably mounted a roller |89. During the counterclockwise rotation of the crank arm |51, the roller |89 engages a formed over ear |9| extending laterally from the lever |55. Theear ISI normally lies-out of the path oi travel oi the roller |89 (Fig. l) but when the mechanism moves to the relatching position (Fig. 2) theear |9 is moved to the Fig. 2position where it is in the path' of the roller |89. Upon rotation of the crank arm |41, the roller |89-engages the ear |9| and-operates the leverV |55 to close the breaker.

During the greater portion of the closing movement only a comparatively light load is imposed' upon the motor. It is during the early part of the closing operation that most of the workof restressing the spring i'il is accomplished so thatv ISS-|95 is connected to operate the motor |39 through a drum switch, a developed view of which is indicated generally at |91. The drum switch issecured on the crank arm shaft |49 for rotation therewith. The circuit for ener- This movement is normally prevented Consequently, as the spring |1|.

gizing the motor |39is also' controlled by an auxiliary.r switch, the contacts |991of which are opentwhenA the breakerisclosed and. closed when the breaker is open. A. manually operated switch 29| -is provided for initiating a closing. operation of the motor; The switch 20| has normally closed contacts 263v and normally open contacts 204 and 205 and. is biased:` to the neutral position shown in Fig.; 3f by springs 201. The drum switch |91 comprises a cylindrical conducting segment 2091 mounted on andA rotatable with a drum or cylinder 2| |f ofv insulating material.

forcooperating with the segment 209 to control the circuits for energizing the motor |39. The contact nger- 2|3 is connected by a wire 223g contact 293, switch 29| and a wire 225 to the conductor |93: The contact' finger 2|5 is connected by means oi a wire 221through the auxiliary contacts |99 and a wire 229 to one terminal of the motor |39-, the other terminali` of the motor being connected directly to the conductor |95. A wire 23| connects the contact. finger 2|1 directly to the conductor |93. They contact' finger 219 is connected by means or" a wire 233, through the normally open contacts 295', switch 29| and the Wire 225 to the conductor. |93.

The contact ngers at the end of a closing operationy rest on the drum 2|`| in substantially the positions shown' in Fig, 8 inwrelation to the conducting segment 209. In this position of the drum switch, a circuit is prepared to energize the motor and automatically reset the crank arm`r |41 (Fig. 1) andthe drum switch upon opening of the breaker. This circuit extends irom the conductor |93, over the wire 225, normally closed contacts 203; wire 223, contact ngers 2fl3and 2|5, at this time in Contact with the portion 299a oi` the segment 299', wire 221, open auxiliary contacts |99rand wire 229 through thc motor` |39 to the conductor |95. This circuit. is` open at the auxiliary contacts |99' when the Circuit breaker is closed. When the breaker is operated to the open position, in the previouslyw described manner, the auxiliary contacts |99 close energizing. the motor |39; The mo.- tor; operating through the reduction gearing (not shown), rotates the crank arm |41 inthe direction of the arrow (Fig. l) from the Fig. l position to approximately the position shown in Fig. 2. Since the crank arm |41 and the drum switch |91 arev keyed to the same shaft, the drum switch is also rotated in the direction indicated by the arrow (Fig. 3). At the point indicated atV 0 on the drum switch, the poition 29a ofthe segment passes from beneath the contact ngers 2| 3 and 2|5, thus opening the circuit therethrough and deenergizing the motor. The motor, however, coacts a short distance before it stops thereby bringing a portion 2091) of the switch segment under the contact lingers 2-|9 and 22|. This prepares a second motor energizing circuit extending from the conductor |93 over the wire 225, normally open contact 2115 of the control switch 20|, wire 233, contact fingers 2 i 9 and 22| and the segment portion 29912 and the wire 229 through the motor to the conductor |95; This circuit is open at the contacts 20|-205 and the motor remains unenergized until the switch 20| is operated toA engage the Contact 205. Closure of thesev contacts energizes the motor 39 over the circuit just.

Five Contact; fingersl 213, 215, 2.|=1, 2|9. and 22|v are providedY the position shown in Fig. 2 to the Fig. 1 position. During this operation the roller |89 on the end of the crank arm engages the ear I9| of the closing lever |55 and operates this lever counterclockwise about the pivot |5| to close the breaker in the previously described manner. During the closing operation the segment 209 engages the contact finger 2|1 at the point indicated at 105 on the segment (Fig. 3). This engagement occurs before the circuit breaker starts to move toward closed position. This establishes a sealing circuit for the motor which shunts the control switch contacts 205 and maintains the motor running throughout the remainder of the closing cycle even if the manual switch is released and the contacts 205 opened. At the point indicated at 240 on the segment 209, the segment separates from the contact fingers 2|1 and 22| and automatically opens the motor circuit. The motor coasts until the drum 2| I comes to rest with the segment 209 in substantially the position indicated in Fig. 3 with relation to the contact fingers. In this position of the mechanism, the roller |89 on the crank arm |41 occupies a position slightly to the right and out of the path of movement of the ear |9| on the closing lever |55, as shown in Fig. l, so that this lever is free to operate to relatch the operating lever 9| to the actuating lever 85 following the next circuit-breaker opening operation.

The circuit breaker is trip-free of the closing mechanism. That is, if the breaker is closed in against a fault, the breaker mechanism will be tripped and moved to the open contact position irrespective of the position of the closing mechanism or energized condition of the closing motor.

The shape of the segment 209 is such that the motor circuit through the contacts 205 will be opened before the breaker contacts touch and before the breaker reaches the closed position in order to prevent pumping if the breaker is closed against a fault with the manual switch 20| held in the position to maintain the contact 205 in closed position. Referring to Fig. 3, it will be noted that the segment 209 is shaped so as to disengage the contact finger 2 I9 at the point designated at 210 or 30 before the segment disengages the contact fingers 2| 1 and 22|. This insures that the circuit through the contacts 205 will be opened and that the motor wil be deenergized as soon as the segment 209 disengages the Contact fingers 2|1 and 22|. Since the contacts 203 are held open so long as the switch 20| is held down the previously described automatic resetting operation will not occur following a tripfree operation of the breaker since the motor energizing circuit through the contacts 203 and the contact fingers 2|3 and 2|5 will be open, consequently the motor cannot be energized again by holding the control switch 20| closed. Thus pumping of the breaker is prevented. When the switch 20| is released, the springs 201 restore it to its central position closing the contacts 203 and opening the contacts 205. Since, at this time, the segment 209 is in contact with the contact fingers 2 I3 and 2|5, and the auxiliary contacts |99 closed when the breaker opened, the motor is energized to reset the mechanism crank to the position shown in Fig. 2 and the drum switch to the reset position. In this position, as previously set forth, the portion 2091) of the segment 209 engages the fingers 2|9 and 22|, so that upon closure of the contacts 205 the 10 motor will again be energized to close the break- The control switch 20| may be located at a point remote from the circuit breaker, for instance, at a control station, and conventional signals such as lights or audible signal means, may be employed to indicate the condition of the breaker. The breaker may also be tripped open from a remotely located control station by operating the manual switch 20| (Fig. 3) into engagement with a contact 204 which, when closed, trips the breaker by means of a conventional shunt trip coil 231. The shunt trip coil is energized over a circuit extending from the conductor |99 over the wire 225, switch member 20|, contact 204, a wire 239, auxiliary contacts 24| closed when the breaker is closed, a wire 243 and the shunt trip coil 231 to the conductor |95.

Having described the invention in accordance with the patent statutes, it is to be understood that various changes and modications may be made in the structural details and combination of elements disclosed without departing from some of the essential features of the invention. It is, therefore, desired that the language of the appended claims be given as reasonably broad interpretation as the prior art permits.

We claim as our invention:

1. In a circuit breaker, a switch member movable to open and closed circuit positions, power operated means for moving said switch member to closed circuit position, an energizing circuit for said power means, trip means operable to cause opening movement of said switch member irrespectively of said power operated means, an auxiliary switch disposed in said circuit to be open when the breaker is closed and closed when the breaker is open, said auxiliary switch .being operative when closed to energize said power operated means, a drum switch operated )by said power operated means connected in said circuit to control the energization of said power means, said drum switch having contact means thereon operative to open said circuit through said auxiliary switch and to prepare a circuit for energizing the power operated means independently of said auxiliary switch, a manually operable switch operative to initiate energization of said power operated means over said prepared circuit, said drum switch being thereafter operative to establish a circuit for energizing said power operated means independently of said auxiliary switch and said manual switch to cause movement of said switch member to closed circuit position and for automatically deenergizing said said power operated means at the completion of the closing movement of said power operated means.

2. In a circuit breaker, a switch member movable to open and closed circuit positions, motor operated mechanism operative at times to move said switch member to closed circuit position, trip means operative to cause opening movement of saidv switch member irrespective of said motor operated mechanism, an energizing circuit for said motor mechanism, an auxiliary switch disposed in said circuit to be open when the breaker is closed and closed when the breaker is opened,` a manually operable control switch having two positions for controlling the energization of said motor, a drum switch operable by said motor mechanism, said drum switch having Contact means thereon operative to effect energization of said motor over a iirst motor control circuit extending through said auxiliary switch l 1 and a rst position of said manual control switch, said drum switch having contact means thereon operative to prepare a second motor control circuit extending through a second position of said manual control switch but independently .of said auxiliary switch and to automatically open said first motor control circuit, said manual control switch being movable to said second position to close said second circuit to initiate energization -of said motor over said second circuit, and said drum switch being further operative to close a third motor control circuit independently of said auxiliary switch and said manual control switch and to open said third circuit at the completion of the closing movement of said mechanism.

3. In a circuit breaker, a switch member movable to open and closed circuit positions, operating mechanism for said circuit breakers, power operated means for actuating said operating mechanism to close the switch member, a circuit for energizing said power operated means, trip means operable to cause opening movement of said switch member irrespective of the power operated means, spring means for `moving said dependently of said auxiliary switcl'r'a manually operable switch in said circuit operative to initiate energization of said power operated means over said prepared circuit, said drum switch `loeing thereafter operative to establish a circuit Vfor energizing said power operated `means independently of said auxiliary switch and said manual switch `to cause `movement of said switch member to closed circuit position and for automatically deenergizing said power operated means 'at`the completion of the closing movement Aof .said power operated means.

4. A circuit breaker comprising 'switch means movable to open and closed circuit positions, an operating member operable to move said switch `means to closed position, means operable to effect opening of said switch means irrespective of the position of said operating member, a closing lever, means connecting said closing lever to lsaid operating member for actuating said operating member to close said switch member, spring means connected at one end to said closing lever at a point substantially intermediate the ends thereof and at the other end lto said'connecting means applying a torque to Ysaid operating member for lmoving said operating member to a :reset position and for moving said closing lever toan operative position, said operating member,

`said closing lever and said spring being adapted to increase the .moment arm with which said torque is applied to provide a greater torque on said operating'member near the end of `a resetting operation than at the beginning of a resetting operation.

5. An operating mechanism for a circuit breaker Icomprising an operating member operable to close said breaker and movable from a closed position to a reset position, a pivoted closing lever, a link at all times connected to said operating member and to said closing lever, power means for engaging and moving said closing lever to said closed position to close said breaker, spring means compressed between said link and a point substantially intermediate the ends of said closing lever and cooperating with said parts to move said operating member to said reset position with a predetermined initial torque and for moving said closing lever to operative position free of said power means, and said parts being adapted toincrease the moment of application of said torque to said operating member to increase the torque on said operating member near the'end of'said resetting movement.

6. An operating mechanism for a circuit breaker comprising an operating member movable to close said circuit breaker, said member being movable from a closed position to a reset'position, a closing lever operable to move said operating member kto close said breaker, a link at all times connecting said closing lever to said operating member, a spring compressed between said link and a point intermediate the ends of said closing lever to apply a predetermined vinitial torque biasing said operating member inresetting direction, said parts being adapted to increase the moment of application of said torque to apply increasing torque to said operating member during the entire movement of said member to reset position.

7. In a circuit breaker, a switch member movable to open and closed circuit positions, operating mechanism comprising an operating member operable to move saidswitch member to closed position, means voperable to cause opening-of the breaker, a closing lever, rigid meansconnecting said closing lever to said operating member, spring means having one end connected to said connecting means at a point adjacent to said operating member and the other end connected to said closing lever for moving said closing ,lever to an operative position and for moving said operating member to a reset position, said connecting means, said closing lever and said spring means being adapted to cause said spring means to apply a greater torque to said operatingmember near the end of a resetting stroke than at the beginning of said resetting stroke, power operated means operable when energized to actuate said closing lever to close said breaker, an energizing circuit for said power operated means, means comprising auxiliary contact means closed upon opening of said breaker and a drum switch for effecting initial energization of said power operated means to cause said power operated means to operate to a predetermined position, manually operated contact means in said circuit for initiating energization of said power means to effect closing of said breaker, and said drum switch being operated by said power means to thereafter control the energization of said power means independently of said manual contact means and said auxiliary contact means.

8. In a circuit breaker, operating mechanism comprising an operating member operable in one direction to close said breaker and in another direction to effect resetting of said mechanism, means operable to effect opening of said breaker, a closing lever, connecting means operatively connecting said closing lever and said operating member, spring means having one end connected to said closing lever at a point between the ends thereof and the other end connected to said connecting means to apply a torque to said operating .member for moving said operating member in 13 resetting direction and for moving said closing lever to an operative position, said parts being adapted to increase the moment of application of said torque to said operating member during a resetting operation to produce a greater torque on said operating member near the end of a resetting stroke than at the start of said resetting stroke, and power operated means disposed to engage said closing lever when said lever is in said operative position and actuate said closing lever to close said breaker.

9. In a circuit breaker, a circuit controlling member biased to open circuit position, an operating member operable to close said breaker and movable to an open circuit position, latch means releasably connecting said controlling member to said operating member, means for releasably restraining said operating member in closed circuit position, electroresponsive means for operating said latch to effect release of said circuit controlling member and permit movement of said circuit controlling member to open position, said circuit controlling member when moved to open position actuating said restraining means to permit movement of said operating member to open position to relatch said operating member to said controlling member, a closing lever, means at all times connecting said closing lever to said operating member for unitary movement, spring means having one end connected to said closing lever at a point substantially intermediate the ends thereof and the other end connected to said connecting means, said spring means upon release of said operating member applying a force to said operating member to move said member to effect relatching of said operating member to said controlling member and to move said closing lever to an operative position, said operating member, said closing lever and said spring being adapted to increase the moment of application of said force to said operating member yto apply an increasing torque on said operating member at the time said latch means relatches during said relatching movement, and power operated means for actuating said closing lever to move said controlling member to closed circuit position.

l0. In a circuit breaker, a switch member movable to open and closed circuit positions, operating mechanism for said circuit breaker comprising an operating member operable to move said switch member to closed circuit position, means releasably connecting said switch member to said operating member, a closing lever, a link connecting said closing lever to said operating member, means for restraining said operating member and said switch member in closed circuit position, said restraining means also restraining said closing lever in an inoperative position, trip means operable in response to predetermined circuit conditions to release said switch member from said operating member to effect opening of said switch member, said switch member during said opening movement operating said restraining means to permit movement of said operating member to reset position to reconnect said operating member to said switch member, resetting spring means operable to effect a resetting operation of said operating member and to move said closing lever to an operative position, said spring means being disposed between said closing lever and said link to appl57 a torque to said operating member and adapted to increase said torque during the latter part of the resetting movement, motor means for operating said closing lever to close said breaker, means comprising an auxiliary switch closed upon opening of said breaker and a drum switch for automatically effecting initial energization of said motor to cause said motor to operate to a predetermined position, a manual switch operable to effect energization of said motor to cause said motor to operate said closing lever and close said breaker, said drum switch being operated by said motor to thereafter automatically control the energization of said motor independently of said auxiliary switch and said manual switch.

11. An operating mechanism for operating a device comprising an operating member movable to actuate said device in one direction and also to accomplish an operative function to a reset position, power operated means for actuating said member in said one direction, a lever movable to operate said member and movable to a reset position, means at all times connecting said operating member and Said lever for unitary movement, a compression spring having one end attached to said connecting means and having the other end attached to said lever at a point substantially intermediate the ends thereof for movement therewith, said spring applying a force to said operating member and to said lever to move said operating member in another direction to said reset position and to move said lever to said reset position independently of said power means, and said parts being adapted to increase the moment arm at which the force of said spring is applied to said operating member during the resetting movement to increase the torque applied to said operating member.

l2. In a circuit breaker, a switch member movable to open and closed circuit positions, operating mechanism for said circuit breaker comprising an operating member operable to move said switch member to closed circuit position, a resettable latch releasably connecting said switch member to said operating member, a closing lever, means operatively connecting said closing lever to said operating member, restraining means for restraining said operating member and said switch member in closed circuit position, said restraining means also restraining said closing lever in an unoperative position, trip means operable in response to predetermined circuit conditions to effect release of said switch member from said operating member to cause opening of said breaker, said switch member during said opening movement eiiecting operation of said restraining means to permit movement of said operating member to a reset position to reconnect said operating member to said switch member, a compression spring having one end connected to said connecting means to apply a force to said operating member biasing said member in resetting direction, the other end of said spring being connected to said closing lever at a point intermediate the ends thereof for movement with said closing lever, said spring, said operating member, said lever and said connecting means being adapted to increase the moment arm with which the force of said Spring is applied to said operating member during a resetting movement to increase the torque applied to said operating member, and power operated means for operating said closing lever to close said breaker.

13. In a circuit breaker, a switch member movable to open and closed circuit positions, operating mechanism for said circuit breaker comprising a pivoted operating member operable to move said switch member to closed circuit position, a resettable latch releasably connecting said switch member to said operating member, a pivoted closing lever, said operating member and said closing lever being movable in opposite directions about their respective pivots, connecting means connecting the free ends of said closing lever and said operating member, means releasably restraining said operating member and said switch member in closed circuit position and for restraining said closing lever in an unoperative position, trip means operable in response to predetermined circuit conditions to release said switch member from said operating member to effect opening of said breaker, said switch member during opening movement operating said restraining means to permit movement of said operating member to a reset position to reset said latch, spring means biasing said operating member in resetting direction with a predetermined torque, said spring means having one end connected to said connecting means at a point adjacent the free end of said operating member and the other end connected to said closing lever at a point substantially intermediate the ends thereof, said parts being adapted to increase the moment of application of said torque to apply a greater torque to said operating member during the latter Vpart of the resetting movement than at the be- 16 ginning of said resetting v'movement to reset said latch, and power operated means for engaging and operating said closing lever and said operating member to close said breaker.

MERL E. HORN. TURELINDSTROM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 667,625 Hopkinson et al Feb. 5, 1901 1,108,254 Scott Aug. 25, 1914 1,157,930 Elden Oct. 26, 1915 1,193,695 Jacobs Aug. 8, 1916 1,807,020 Van lSickle et al. May 26, 1931 1,853,745 Rea Apr. 12, 1932 1,901,406 Nye Mar. 14, 1933 2,034,145 Linde Mar. 17, 1936 2,125,835 MacNeill Aug. 2, 1938 2,177,014 Austin Oct, 24, 1939 2,264,982 Johnson Dec. 2, 1941 2,264,990 Lindstrom et al Dec. 2, 1941 2,304,865 Thumin Dec. 15, 1942 

